Statistical analyses of data were performed with STATISTICA Version 7.0 (StatSoft). To compare mean values analysis of variance (ANOVA) was applied. The means were compared by the Tukey’s multiple rangetest (P = 0.05). For analyses of iodine changes during storage the correlations between variables were investigated by regression analysis (Pike,1986). To compare rates of change, the half-life t1/2 was determined,i.e. the time in which the initial iodine content decreased by half.